Ready-to-eat ("R-T-E") breakfast cereals are popular packaged food items. R-T-E cereals exist in large numbers of varieties including puffed and unpuffed, natural or presweetened, and including a wide variety of cereal compositions.
One problem in cereal processing resides in flavor development. Many consumers prefer puffed cereals, and particularly R-T-E cereal in complex shapes such as torroids or rings or other shapes such as stars. The term "complex shapes" is used herein in reference to or equivalently with non-convex shapes. Such complexly shaped puffed cereals are generally prepared by gun puffing moist (e.g., 10% to 14% moisture) cereal pellets. While popular, many consumers enjoy the flavor of toasted cereals. Unfortunately, it is difficult to evenly toast puffed R-T-E cereals, especially those cereal pieces having a complex shape using conventional toasting equipment and methods. Generally, such known toasting techniques involve intense heating including radiant and/or conduction heating which involve heat transfer from the exterior of the piece inward. Due to the low density of puffed pieces which insulatively resists conductive heat transfer and due to complex shapes, undesirable scorching of the exterior surface can occur prior to the development of desirable toasted flavor by any significant weight of the interior of the cereal piece.
The operation of the gun puffing apparatus can be adjusted to provide some degree of toasting to the resulting puffed cereal pieces. Primarily, the adjustment involves retaining the pellets within the cereal gun for longer residence times so as to increase the pellets' exposure to the elevated temperature and pressure conditions within the gun. While effective to some degree, increasing the residence time of the pellets within the gun necessarily unfortunately decreases the throughput of pellets through the gun. Since cereal puffing guns are complex and capital and energy intensive manufacturing equipment, even modest reductions in capacity or throughput can materially increase production costs.
In view of the state of the art, there is a continuing need for improvements in the cereal processing art for preparing R-T-E cereals exhibiting increased stability.
Accordingly, it is an object of the present invention to provide improved cereal processing methods for the production of R-T-E cereals which exhibit increases in shelf stability.
Still another object of the present invention is to provide methods for cereal processing which can be readily practiced in present commercial cereal processing plants without requiring extensive modification of existing cereal processing processes or equipment.
Another object of the present invention is to provide cereal processing method improvements which can reduce the cost of cereal processing by reducing plant start-up time.
Another object of the present invention is to provide cereal processing methods which can provide improvements in product stability so as to allow the reduction or elimination of addition of stabilizers to cereal compositions.
Another object of the present invention is to provide interior toasting of puffed R-T-E cereal pieces.
Still another object of the present invention is to provide interior toasting of complexly shaped puffed R-T-E cereal pieces.
Surprisingly, the above objects can be realized and the present invention provides methods for dramatically increasing the flavor and stability of puffed R-T-E cereals. The present invention involves subjecting the finished puffed R-T-E cereal or a cereal base to a brief exposure to a high intensity microwave field. For sugar coated embodiments, the cereal base can be microwave heated prior to the application of the topical coating. In its product aspect, the present invention resides in finished products exhibiting enhanced shelf stability.